This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. The overarching objective of this program is to deepen our understanding of the mechanisms of additive neurological injury from methamphetamine (METH) and HIV. Recognizing that infection with the Hepatitis C virus may also contribute to such injury and give frequent HCV infection wtih METH abusers, the program will undertake the first systematic exploration of the more complex interactions amount METH, HIV and HCV in determining neurobehavioral disturbance.